Plasma Protein Oxidation and Triglyceride Levels in Sickle Cell Anemia.

A mutant and unstable hemoglobin is characteristic in sickle cell anemia (SCA) with an increased formation of methemoglobin, hemichrome and haemin. Increased oxidative stress and altered lipid balance in the plasmas of SCA patients have been documented previously. Lower total plasma cholesterol (TC) and higher-than-avarage triglyceride (TG) levels have also been reported in SCA patients compared to healthy controls. Plasma phospholipids (PL) were normal or increased according to various studies. However, to our knowledge only a few reports documented the plasma protein oxidation in SCA patients. In this study protein oxidation, lipid levels, bilurubin levels and their probable correlation were investigated in the plasmas of SCA patients, carriers and healthy controls.

15 SCA patients, 10 carriers and 10 healthy controls were included in the study. The patients had not been transfused and hospitalized and had no crisis for the last three months. The oxidation status of plasma and its proteins were detirmined by total sulfhydryl (T-SH) and protein carbonly levels respectively. TC, TG and bilurubin levels were detirmined in the plasma and PL levels were detirmined in the lipid extract from plasma.

SCA patients had lower T-SH levels compared to controls (p=0.003) and higher protein carbonyl levels compared to carriers (p=0.001) and healthy children (p=0.032). T-SH values were 417.41±77.90 μM, 457.46±106.26 μM, 522.59±77.18 μM and protein carbonyl levels were 0.93±0.15 nmol/mg protein, 0.74±0.08 nmol/mg protein , 0.82±0.05 nmol/mg protein for patients, carriers and controls respectively. Significantly lower mean TC levels than controls (p<0.0001) and higher TG levels than carriers (p=0.001) were observed in SCA patients. TC levels were 116.67±23.60, 127.53±22.40, 151.62±16.53 and TG levels were 89.31±23.50 mg/dl, 60.94±9.18 mg/dl, 82.96±21.06 mg/dl for patients, carriers and controls respectively. Phospholipid levels were not different between the groups. TG levels were positively correlated to protein carbonyl levels (p=0.002) and to bilirubin levels (p=0.033). Bilurubin levels and protein carbonyl levels are also positively correlated (p<0,0001).

Alteration of lipid balance besides protein oxidation and hemolysis were observed in the plasmas of SCA patients compared to the carriers and healthy group. The positive correlation between total bilurubin, TG and carbonyl levels indicates that oxidative stress may affect the SCA plasma extensively, ie. lipids, proteins and erythrocytes are all affected.

No relevant conflicts of interest to declare.